I'm knitting a lace scarf. Everything is going well until I come to this in the pattern. YOS2KP. I know what it means but it makes the row two stitches less than the required 33 stitches. I always end up with 31 stitches. I've counted and counted. It works out mathematically, but not in reality. I am completely out of my mind with puzzlement. Any help out there? Whatever am I doing wrong?

There should be a comma there, the YO is separate from the s2kp which means, slip 2, k1 and pass the slip sts over. It is a double dec which takes 3 sts into 1. There may be another YO there to offset the dec and keep the st number the same, but maybe not. A link to the pattern or posting the row this appears in would be helpful.